REW can only control the interface sample rate if you use ASIO or WASAPI Exclusive Java drivers (device names starting EXCL). If you use the standard Java drivers the OS will resample the data to the rate in REW if the device sample rate is different and you will see the effects of the resampling.
If you choose "Plot harmonics at the harmonic frequency" then the 3rd harmonic of 1 kHz will be plotted at 3 kHz. The whole 3rd harmonic graph is shifted 3 times higher in frequency than when you do not select that option. The graph legend show figures for the cursor position, so if you have...
I would guess that the driver doesn't like the frequent starting and stopping of the stream. You can also try the WASAPI exclusive driver, that may be more consistent (Java driver, device name starting EXCL).
The starts are different because one response has a start time slightly greater than zero and the other has a start time slightly less than zero, the graph adjusts the axis start to a suitable 10 ms increment. I can revise the way the graph start is chosen to reduce the effect of small...
Builds updated today (beta 104) with these changes:
Changed: Overlays window has improved responsiveness and reduced memory use for large measurement sets
Changed: The widths of the legend panel entries adapt to accommodate the longest measurement name
Changed: Sorting measurement names and the...